1. Technical Field
This invention pertains generally to improvements in traction cleats for shoes and, more particularly, to an improved mounting and locking structure on a cleat by which the cleat can be selectively secured to and released from a particular commercially available retaining member mounted in a shoe sole. The particular retaining member is part of an attachment system manufactured by MacNeill Engineering Co., Inc. under the trademark Q-LOK(copyright), and is disclosed in a variety of forms in U.S. Pat. Nos. 5,768,809 (Savoie ""809), 6,151,805 (Savoie ""805) and 6,332,281 (Savoie ""281). The entire disclosures in those patents are incorporated herein by reference.
2. Discussion of Related Art
The Savoie ""809 patent discloses a receptacle with an interior cavity having an opening formed in the receptacle bottom wall for receiving a connector of a cleat or spike. The opening has three identical and symmetrically disposed generally semi-circular lobes and is adapted to receive the cleat connector which has a central base post with three radially extending retaining members at its distal end. The three retaining members are curved to define a trilobal pattern matching the three receptacle lobes. The connector is inserted into the receptacle by first aligning the retaining member lobes with respective lobes of the receptacle opening and then axially sliding the retaining members through the opening and into the receptacle cavity. Within the cavity are three cantilevered resilient fingers or spring arms biased radially inward and designed to engage and hold respective installed retaining members.
When the inserted retaining members are rotated about the connector axis, the retaining members become axially misaligned from the lobes of the receptacle opening. A shelf surrounding the receptacle opening is defined by the interior surface of the receptacle bottom wall and axially compresses the retaining members to retain them in the cavity. The shelf is ramped in each of the three sections adjacent a respective opening lobe, thereby gradually restricting the axial depth of the cavity in three locations. Rotation of the inserted retaining members causes a protruding portion of the arcuate edge of each retaining member to contact a curved tip of a respective finger to allow the retaining member to be turned past the angular location of the finger. Once the protruding edge of a retaining member passes the location of the finger, the finger springs back to nearly its original shape so that the tip of the finger abuts the side of an adjacent lobe of a retaining member. This allows the cleat to be removed, but only by exerting sufficient torque to bend the fingers away from the surfaces of the retaining members which requires considerably greater torque than that required during installation of the retaining member. Coincident with the fingers locking into place, the protruding edge of a retaining member is blocked from further movement by stops protruding into the cavity from the receptacle outer wall. The depth of each retaining member is gradually reduced but more gradually than the cavity depth so that the engagement of the retaining member is gradually tightened with rotation. In other words, the gradual restriction of the cavity receptacle depth is designed such that each retaining member is increasingly compressed axially as the cleat is rotated to securely hold the cleat in place.
One problem with this design relates to the use of precisely matching arcuate lobe contours on the retaining members and the receptacle cavity opening. These matching contours require precise axial as well as rotational alignment during axial insertion of the retaining members into the cavity. In addition, the smoothly arcuate periphery makes it difficult for the resilient cavity fingers to reliably perform the function of locking the retaining member against reverse rotation. In fact, this has resulted in Savoie providing a notch in the retaining member periphery in some of the embodiments disclosed in the Savoie ""809, ""805 and ""281 patents.
In addition, the use of a central post on the cleat connector prevents any resilient radial contraction of the retaining members, a feature which is desirable to facilitate both insertion of the retaining members into and their removal from the receptacle cavity.
It is an object of the present invention to provide an improved connector for a cleat suitable for insertion and engagement in the receptacle disclosed in the Savoie ""809 ""805 and ""281 patents.
It is another object of the invention to provide an improved connector and method for attaching a traction cleat to a Q-LOK(copyright) system without the disadvantages noted hereinabove.
A further object of the present invention is to provide a method and apparatus for simplifying the insertion of a replacement cleat into a receptacle mounted in a shoe sole.
The aforesaid objects are achieved individually and in combination, and it is not intended that the present invention be construed as requiring two or more of the objects to be combined unless expressly required by the claims attached hereto.
In accordance with the present invention, an improved traction cleat is provided with a connector that fits into and lockingly engages the receptacle of the aforementioned Savoie patent attachment system. The connector, instead of having a rigid central post from which three retaining members radially extend, has a plurality of independent posts, one for each retaining member. The posts are preferably symmetrically disposed about and slightly radially spaced from the central longitudinal axis of the cleat, and can be pivotally flexed slightly during insertion and removal of the connector relative to the connector cavity. The retaining members project radially outward from respective posts and are peripherally contoured as a series of adjacent planar surfaces rather than arcuately with a curvature to match the lobes of the receptacle opening. The linear junctions defining the intersections between adjacent outer facets or surfaces of the retaining members are radially spaced from the cleat longitudinal axis by a distance slightly less than the radial distance of the outermost portion of the lobes of the receptacle opening from the receptacle longitudinal axis.
When inserting the cleat connector into the receptacle opening, the faceted retaining members need only be generally aligned (as opposed to strict axial and rotational alignment) with the receptacle lobes. When one of the cleat retaining members is placed partially in one of the receptacle opening lobes, even if the cleat longitudinal axis is skewed relative to the receptacle longitudinal axis, the cleat can be moved laterally to force the partially inserted retaining member against the receptacle lobe edge. The force causes the post supporting that retaining member to resiliently pivot radially inward to reduce the overall radial dimension of the three-post assembly. At the same time, the linear edge of the retaining member that is in contact with the lobe edge act as a pivot to naturally turn the cleat to facilitate alignment of the retaining member with the lobe. This serves to similarly align the other two retaining members with respective receptacle opening lobes. The result is a smooth fit and insertion of the cleat connector into the receptacle cavity.
When the inserted retaining members are rotated, each receptacle finger ultimately abuts a particular perimetric facet or planar surface that is oriented at an angle to the finger thus preventing inadvertent reverse rotation and loosening of the cleat in the receptacle while permitting reverse rotation in response to intentionally applied torque during removal of the cleat.
The above and still further objects, features and advantages of the present invention will become apparent upon consideration of the following definitions, descriptions and descriptive figures of specific embodiments thereof wherein like reference numerals in the various figures are utilized to designate like components. While these descriptions go into specific details of the invention, it should be understood that variations may and do exist and would be apparent to those skilled in the art based on the descriptions herein.